JPH04160239A - Reservoir tube for liquid pressure type shock absorber and its manufacture - Google Patents

Abstract

PURPOSE:To make the whole of a shock absorber small in size and light in weight by forming a reservoir tube into a cylindrical shape one end of which is blocked, of light alloys such as aluminum, and thereby integrally forming projected sections extending in the axial direction, in the inner surface. CONSTITUTION:A reservoir tube 1 made of light alloys such as aluminum. is formed into a cylindrical body 11 the lower end of which is blocked, and its upper surface is formed with three stripes of projected sections 1a extending in the axial direction, so that they are integrally formed while being equally spaced by the central angle of 120 deg.. The bottom surface of the tube 1 is formed with three projected sections 1b which are continuously extended from each lower end of three stripes of the projected sections 1a wherein the projected sections 1b are not extended to the center of the tube 1, so that they are mutually parted. And each upper end of the projected sections 1a is formed with the engaging section 1c of a cylindrical cap 2 along each specified range, and the upper outer circumference of the tube 1 is formed with a male screw section 1d. By this constitution, the reservoir tube 1 can be made light in weight, and also can be made small in outer diameter with the wall thickness thinned and also with each projected section 1a reinforced, so that the whole of a shock absorber can thereby be practically made small in size and light in weight.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention relates to a reservoir for a hydraulic shock absorber that is attached to the outside of a cylinder of a hydraulic shock absorber to form a reservoir chamber between the cylinder and the outer peripheral surface of the cylinder. The present invention relates to a tube and its manufacturing method.

[Prior Art 1] Conventionally, the reservoir tube of this type of hydraulic shock absorber was made of iron and was therefore heavy.

Therefore, for example, in the case of vehicle-mounted hydraulic shock absorbers that are strongly required to be lightweight, the heavy reservoir tube has been a major obstacle in reducing the weight.

[Problems to be Solved by the Invention I] In order to reduce the weight of the reservoir tube, it is conceivable to make it made of aluminum.

However, in order to ensure a certain level of rigidity, the wall thickness must be increased, which inevitably results in a larger outer diameter (resulting in an increase in the overall size of the shock absorber). In the case of an on-vehicle hydraulic shock absorber that is mounted on a vehicle, there is a problem in that it tends to interfere with the vehicle body, etc., making it difficult to mount it.

An object of the present invention is to solve the above-mentioned conventional problems and provide a lightweight and compact reservoir tube for a liquid shock absorber, and a method for manufacturing the same.

[Means for Solving the Problems 1] The reservoir tube of the hydraulic shock absorber of the present invention is formed into a cylindrical shape with one end closed by a light metal such as aluminum, and has a protrusion extending along the axial direction on the inner surface. It is characterized by being molded at one end.

In addition, in the method of manufacturing a reservoir tube for a hydraulic shock absorber according to the present invention, one end of a cylindrical body made of a light metal such as aluminum, which has a protrusion extending along the axial direction on the inner surface, is closed by spinning processing to form a reservoir tube. Characterized by manufacturing tubes.

[Function 1] In the present invention, the reservoir tube is made of a light metal such as aluminum, and a protrusion extending in the axial direction is integrally formed on the inner surface of the reservoir tube, thereby reducing the weight of the reservoir tube and at the same time, reducing the weight of the reservoir tube by the protrusion. Reinforcement makes it possible to reduce the wall thickness and reduce the outer diameter, making the entire shock absorber smaller and lighter.

【Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, reference numeral 1 denotes a reservoir tube (hereinafter simply referred to as "tube") made of a light metal such as aluminum, and is formed into a cylindrical shape with a closed lower end. The inner surface of the tube l has three protrusions 1a extending in the axial direction with a central angle of 1.
Three protrusions 1b are formed on the bottom surface of the tube 1 and continuously extend from the lower end of each of the three protrusions 1a. These protrusions 1b do not extend to the center of the tube 1 and are spaced apart from each other. Further, the upper end of the protrusion 1a is cut away over a predetermined range, and a fitting part 1c for a cylindrical cap 2, which will be described later, is formed in that part. Further, a male threaded portion 1d is formed on the outer periphery of the upper portion of the tube 1.

A buffer as shown in FIG. 1 is incorporated into such a tube 1. That is, a cylindrical cylinder 4 whose end is closed by a cap 2 and a bottom valve 3 is inserted into the tube 1, and the cylinder 4 is tightened by a bound stopper 5 screwed onto the male threaded portion 1d of the tube 1. is fixed. Cylinder 4 is tube 1
Proper installation is guided into position by the protrusion la,
Its tilting is prevented, and the protrusion 1b of the tube 1 serves as a seat for the bottom valve 3. A reservoir chamber R3 is formed between the inner peripheral surface of the tube 1 and the outer peripheral surface of the cylinder 4. Although this reservoir chamber R3 is defined by three protrusions 1a on the outer peripheral surface of the cylinder 4, it communicates with the lower side of the bottom valve 3.

The interior of the cylinder 4 is defined by a piston 7 connected to a piston rod 6 into first and second cylinder chambers R1 and R2. Piston 7 and bottom valve 3
An oil passage equipped with a valve (not shown) is formed in each of the pistons, and when the piston 7 moves up and down, the oil sealed in the first and second cylinder chambers R1 and R2 flows into the oil chamber of the piston 7. A predetermined damping force is generated by the flow resistance at that time. Further, gas is sealed in the reservoir chamber R3, and the second cylinder chamber R
The oil in 8 passes through the oil passage of bottom valve 3 to reservoir chamber R.
Go in and out within 8.

In FIG. 1, S is a stopper with a buffer material for regulating the upper limit of movement of the piston rod 6, 8 and 9 are sealing materials, and IO is an attached ring.

The tube 1 incorporated in such a hydraulic shock absorber is made of a light metal such as aluminum, so it is lightweight, and since it is reinforced by the protrusion 1a integrally formed on its inner surface, the wall thickness can be reduced and the tube 1 can be made externally. The diameter can be made smaller. As a result, the entire shock absorber can be made smaller and lighter.

Next, a method for manufacturing the tube 1 will be explained.

First, a cylindrical body 11 made of a light alloy such as aluminum as shown in FIG. 2 is prepared. On the inner surface of the cylindrical body 11,
Three protrusions 1a extending in the axial direction are integrally formed at equal intervals with a center angle of 120°.

Next, the lower end of the cylindrical body 11 is subjected to a spinning process to close it as shown in FIG. That is, while rotating the cylindrical body 11 about its axis, a spatula or roller is pressed from the outside to squeeze and close the lower end of the cylindrical body 11.

As a result, the lower portion of the protrusion 1a extends along the bottom surface of the cylindrical body 11.

Thereafter, as shown in FIG. 4, the lower end of the protrusion 1a extending on the bottom surface of the cylindrical body 11, that is, the part near the center, is cut to form the protrusion 1b, and the upper end of the protrusion 1a is cut. is removed to form a fitting portion 1c of the cap 2, and a male threaded portion 1d is further formed to complete the tube 1.

[Effect of the Invention 1] As explained above, according to the present invention, the reservoir tube is made of a light metal such as aluminum, and the protrusion extending in the axial direction is integrally formed on the inner surface of the reservoir tube. At the same time, the reinforcement by the protrusions allows the wall thickness to be reduced and the outer diameter to be reduced.

As a result, the entire shock absorber can be made smaller and lighter.

Moreover, the protrusion can also have the function of positioning the cylinder installed in the reservoir tube.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a shock absorber equipped with a reservoir tube of the present invention, FIG. 2(a) is a plan view of a cylindrical body shown for explaining the manufacturing method of the present invention, and FIG. 2(b) is a sectional view taken along the line ■-■ in FIG. 2(a), FIG. 3(a) is a plan view for explaining the process of processing the cylindrical body shown in FIG. 2(a), and FIG. b) is a sectional view taken along the line ■-■ in Fig. 3(a), Fig. 4(a) is a plan view for explaining the state of completion of processing of the reservoir tube shown in Fig. 2(a), Figure 4(b)
is a sectional view taken along the line IV-IV in FIG. 4(a). DESCRIPTION OF SYMBOLS 1... Reservoir tube, 1a... Protrusion, 11... Cylindrical body.

Claims (1)

[Scope of Claims] 1) A hydraulic type characterized by being formed into a cylindrical shape with one end closed by a light metal such as aluminum, and having a protrusion extending along the axial direction integrally formed on the inner surface. Buffer reservoir tube. 2) A reservoir for a hydraulic shock absorber, characterized in that the reservoir tube is manufactured by closing one end of a cylindrical body made of a light metal such as aluminum by spinning processing and having a protrusion extending along the axial direction on the inner surface. Method of manufacturing tubes.